This invention relates to sealing devices, and is more particularly directed to disposable entrance seals to be used on an external opening of a biopsy channel, the latter typically being included in a medical endoscope.
Current biopsy seals are typically formed of a two-part metal holder and a pair of slitted membranes held in the holder. The slits of the membranes are disposed crosswise to each other and the holder, being threaded, is screwed into a receptacle in the external side of an endoscope biopsy channel.
When it is desired to take a tissue sample, an elongated forceps, with a loop or claw at its distal end, is inserted through the crossed slits into the channel and after obtaining the tissue sample is extracted through the channel and out through the slits of the seal.
The forceps or other instrument is of round external cross-section, but the crossed slits, once penetrated, do not assume a circular shape. Pulsing of fluid pressures in the biopsy channel can cause leakage, and in some cases squirting, of a patient's body fluids out of the seal. This can present hygienic problems to the attending physicians and other medical personnel, especially if the patient being examined has a contagious condition.
The typical seal as described above is not disposable, and must be taken apart and cleaned between uses. This adds to the difficulty of carrying out an endoscopic diagnosis and adds significantly to the cost of examination.
Also, in a typical endoscope, the external entrance to a biopsy channel has no provision for convenient attachment of usual, standard medical devices, thus increasing the difficulty of necessary steps, such as the injection of normal saline solution or water into the biopsy channel, or the sampling of body fluids by withdrawing them into a syringe. For this purpose, a standard luer lock fitting should be provided at the biopsy channel entrance, but no such fitting has been employed at the entrance.
Previously proposed disposable biopsy channel entrance seals do not ensure good seals against insertion of a medical instrument, and the entrance to the channel does not provide for attachment of a typical syringe, as it will not attach to a standard luer lock fitting.